#define _CRT_SECURE_NO_WARNINGS 1
#include<stdio.h>
int main()
{
	int a, b, c, d;
	scanf("%d %d %d %d", &a, &b, &c, &d);
	if ((a>b)&&(a>c)&&(a>d))
		printf("%d\n", a);
	else if ((b >= a) && (b >=c) && (b >= d))
		printf("%d\n", b);
	else if ((c >= a) && (c >= b) && (c >= d))
		printf("%d\n", c);
	else if ((d >= a) && (d >= b) && (d >= c))
		printf("%d\n", d);
	
		return 0;
}